Answer:
A) m = 1600 kg
, B) p = 3.2 10⁴ kg m / s
, C) Δp = - 3.2 10⁴ kg m / s
D) t = 51.6 s
Explanation:
A) They indicate the weight of the vehicle W = 15680 N
weight is the attraction of the earth on a body
W = m g
m = W / g
m = 15680 / 9.8
m = 1600 kg
B) The momentum is defined by
p = m v
p = 1600 20
p = 3.2 10⁴ kg m / s
C) the moment change is
Δp = p_{f} -p₀
as the vehicle stops the final speed is zero and therefore the moment is zero
ΔP = 0 - p₀
Δp = - 3.2 10⁴ kg m / s
D) Let's use Newton's second law
F = m a
a = F / m
a = 6.2 102/1600
a = 0.3875 m / s²
Now we can use kinematics, note that as the vehicle stops, the relationship must be opposite to the speed
v = v₀ - a t
v = 0
0 = v₀ - a t
t = v₀ / a
t = 20 / 0.3875
t = 51.6 s
Explanation:
False
electron and proton attract each other
1.It is the upward force exerted by the ground that pushes you up, but this force can never exceed your weight.
2) You are able to spring up because the earth exerts a force upward on you that is stronger than the downward force you exert on the earth.
3) When you push down on the earth with a force greater than your weight, the earth will push back with the same magnitude force and thus propel you into the air.
4) When you jump up the earth exerts a force F1 on you and you exert a force F2 on the earth. You go up because F1 > F2.
<span>5) Since the ground is stationary, it cannot exert the upward force necessary to propel you into the air. Instead, it is the internal forces of your muscles acting on your body itself that propels the body into the air.</span>
Since weight is motionless, net force is equal to zero.
According to Newton's 2nd law of motion,
T - mg = 0-----------(T = tension, mg = weight of mass)
4.75 = m x 9.8
m = 4.75/9.8
m = 0.48 kg.
Hope this helps\!
